Spectral features of the geodesic acoustic mode and its interaction with turbulence in a tokamak plasmaa)
Spectral features of the geodesic acoustic mode and its interaction with turbulence in a tokamak plasmaa)
复制标题
DOI：
10.1063/1.2838242
复制
发表时间：
2007-11
影响因子：
2.2
通讯作者：
中科院分区：
文献类型：
--
作者：
在环六旗2A托卡马克装置上首次测量了测地声模（GAM）的三维波数和频谱。该光谱为广义相对论提供了明确的证据，其特征为kθ=k θ =0，krρi <$0.04 −0.09，半峰全宽Δkrρi <$0.03 −0.07。局域化的GAM包被观察到在径向方向上向外传播，具有几乎相同的相位和群速度。径向电场和密度波动的包络线被观察到由GAM调制。通过比较实验结果与模型信号包络分析的结果，确定了包络调制的机理。结果表明，Er涨落的包络调制主要是由能量守恒三元组相互作用中GAM产生过程中GAM的直接调节引起的，而密度涨落的包络调制则是由GAM剪切效应引起的。
The three-dimensional wavenumber and frequency spectrum for the geodesic acoustic mode (GAM) has been measured in the HuanLiuqi-2A tokamak for the first time. The spectrum provides definite evidence for the GAM, which is characterized by kθ=kϕ=0 and krρi≈0.04−0.09 with the full width at half-maximum Δkrρi≈0.03−0.07. The localized GAM packet is observed to propagate outward in the radial direction with nearly the same phase and group velocity. The envelopes of the radial electric field and density fluctuations are observed to be modulated by the GAM. By comparing the experimental result with that of the envelope analysis using model signals, the mechanism of the envelope modulation has been identified. The results strongly suggest that the envelope modulation of the Er fluctuations is dominantly caused by the direct regulation of the GAM during the GAM generation in the energy-conserving triad interaction, and the envelope modulation of the density fluctuations is induced by the GAM shearing effect, which...